Substrate processing apparatus, heating apparatus, ceiling heat insulator, and method of manufacturing semiconductor device

ABSTRACT

A ceiling heat insulator installed above a side wall heat insulator of a heating apparatus for a substrate processing apparatus for processing a substrate is provided. The ceiling heat insulator includes a gas-flow path installed therein to allow a cooling gas to pass therethrough so that the ceiling heat insulator has a solid cross-sectional area in an outer edge side of the ceiling heat insulator that is smaller than that in a center side of the ceiling heat insulator.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority fromJapan Patent Application No. 2014-021223, filed on Feb. 6, 2014, theentire contents of which are incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to a substrate processing apparatus, aheating apparatus, a ceiling heat insulator, and a method ofmanufacturing a semiconductor device.

BACKGROUND

A semiconductor manufacturing apparatus has been known as an example ofa substrate processing apparatus, and a vertical-type diffusion CVDapparatus has been known as an example of a semiconductor manufacturingapparatus. In such a substrate processing apparatus, when the substrateis processed, a heating apparatus is used to heat the substrate.

As an example of the heating apparatus, there has been known anapparatus having an annular side wall heat insulator installed outside areaction container, a heating element installed on an inner surface ofthe side wall heat insulator, and a ceiling heat insulator installedabove the side wall heat insulator, which heats a substrate within thereaction container by means of the heating element and supplies acooling gas to a space between the reaction container and the side wallheat insulator to cool the heated substrate, in the related art. In sucha heating apparatus, the cooling gas supplied to the space between thereaction container and the side wall heat insulator is dischargedoutside of the heating apparatus through the ceiling heat insulator.

In this type of the heating apparatus, however, since the cooling gas isdischarged through the ceiling heat insulator, a gas-flow path for thecooling gas needs to be installed on the ceiling heat insulator. Thus, adifference in thermal insulation is caused depending on portions of theceiling heat insulator to result in a degradation of in-planetemperature uniformity of the substrate.

SUMMARY

The present disclosure provides some embodiments of constitution, whichare capable of improving in-plane temperature uniformity of a substrate.

According to an aspect of the present disclosure, there is providedconstitution, including: a reaction container configured to accommodatea substrate; and a heating apparatus having a side wall heat insulatorinstalled at an outer circumference of the reaction container, a ceilingheat insulator installed above the side wall insulator, a heatingelement installed on an inner wall of the side wall heat insulator, anda cooling gas flow path installed between the reaction container and theside wall heat insulator, wherein the ceiling heat insulator isconfigured to include an gas-flow path installed therein to allow acooling gas to pass therethrough so that the ceiling heat insulator hasa thickness in an outer edge side of the ceiling heat insulator that issmaller than that in a center side of the ceiling heat insulator.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view illustrating a substrate processingapparatus according to an embodiment of the present disclosure.

FIG. 2 is a perspective view schematically illustrating a heateraccording to an embodiment of the present disclosure.

FIG. 3 is an enlarged cross-sectional view of a ceiling heat insulatoraccording to an embodiment of the present disclosure.

FIG. 4 is a top view of a lower heat insulator according to anembodiment of the present disclosure.

FIG. 5 is a bottom view of the lower heat insulator according to anembodiment of the present disclosure.

FIG. 6 is a cross-sectional view of the lower heat insulator in FIG. 4,taken along line A-A.

FIG. 7 is a top view of an upper heat insulator according to anembodiment of the present disclosure.

FIG. 8 is a bottom view of the upper heat insulator according to anembodiment of the present disclosure.

FIG. 9 is a cross-sectional view of the upper heat insulator of FIG. 8,taken along line B-B.

FIG. 10 is a view illustrating a flow of a cooling gas within theceiling heat insulator according to an embodiment of the presentdisclosure.

FIG. 11 is a view illustrating temperature distribution in across-section of a wafer when a heater according to an embodiment of thepresent disclosure is used.

FIG. 12 is a view illustrating a temperature transition of a wafer whena heater according to an embodiment of the present disclosure is used.

FIG. 13 is a schematic view illustrating an example of a heater withouta cooling function by a cooling gas according to an embodiment of thepresent disclosure.

FIG. 14 is a view illustrating a temperature distribution in across-section of a wafer when the heater of FIG. 13 is used.

FIG. 15 is a view illustrating a temperature transition of a wafer whenthe heater of FIG. 13 is used.

FIG. 16 is a schematic view illustrating an example of a heater having acooling function using cooling gas.

FIG. 17 is a view illustrating a temperature distribution in across-section of a wafer when the heater of FIG. 16 is used.

FIG. 18 is a schematic view illustrating another example of a heaterhaving a cooling function using a cooling gas.

FIG. 19 is a view illustrating a temperature distribution in across-section of a wafer when the heater of FIG. 18 is used.

FIG. 20 is a view illustrating a temperature transition of a wafer whenthe heater of FIG. 18 is used.

FIG. 21 is a cross-sectional view illustrating a first modification of aceiling heat insulator according to an embodiment of the presentdisclosure.

FIG. 22 is a cross-sectional view illustrating a second modification ofa ceiling heat insulator according to an embodiment of the presentdisclosure.

FIG. 23 is a cross-sectional view illustrating a third modification of aceiling heat insulator according to an embodiment of the presentdisclosure.

FIG. 24 is a cross-sectional view illustrating a fourth modification ofa ceiling heat insulator according to an embodiment of the presentdisclosure.

FIG. 25 is a plan view of a lower heat insulator representing the fourthmodification of the ceiling heat insulator according to an embodiment ofthe present disclosure.

FIG. 26 is a bottom view of the lower heat insulator representing thefourth modification of the ceiling heat insulator according to anembodiment of the present disclosure.

FIG. 27 is a plan view of a lower heat insulator representing a fifthmodification of the ceiling heat insulator according to an embodiment ofthe present disclosure.

FIG. 28 is a bottom view of the lower heat insulator representing thefifth modification of the ceiling heat insulator according to anembodiment of the present disclosure.

FIG. 29 is a bottom view of an upper heat insulator representing thefifth modification of the ceiling heat insulator according to anembodiment of the present disclosure.

DETAILED DESCRIPTION

Hereinafter, embodiments of the present disclosure will now be describedin detail with reference to the drawings.

FIG. 1 is a cross-sectional view illustrating a substrate processingapparatus appropriately used in an embodiment of the present disclosure.

As illustrated in FIG. 1, a substrate processing apparatus 1 includes aprocessing furnace 202. The processing furnace 202 includes a heater 206as a heating apparatus. The heater 206 has a cylindrical shape and issupported by a heater base 251 as a support plate so as to be installedvertically.

A process tube 203 as a reaction container is disposed within the heater206 and has a concentric circle shape with the heater 206. In otherwords, the heater 206 is disposed outside the process tube 203. Theprocess tube 203 includes an inner tube 204 as an internal reactioncontainer and an outer tube 205 as an external reaction containerinstalled outside the inner tube 204. The inner tube 204 is formed of aheat resistant material such as, for example, quartz (SiO₂) or siliconcarbide (SiC), and has a cylindrical shape with an upper end and a lowerend opened. A process chamber 201 is formed within the inner tube 204,and configured to accommodate wafers 200 as substrates, which arealigned to be horizontally stacked in multiple stages in a verticaldirection by a boat 217. The outer tube 205 is also formed of a heatresistant material such as, for example, quartz or silicon carbide, andhas its inner diameter greater than an outer diameter of the inner tube204. The outer tube 205 has a cylindrical shape with the upper endclosed and the lower end opened and is disposed in a concentric formwith the inner tube 204.

A manifold 209 is disposed below the outer tube 205 in a concentric formwith the outer tube 205. The manifold 209 is made of, for example, astainless steel, and formed to have a cylindrical shape with upper andlower ends opened. The manifold 209 is engaged to the inner tube 204 andthe outer tube 205 to support them. Further, an O-ring 220 a as a sealmember is installed between the manifold 209 and the outer tube 205. Themanifold 209 is supported by the heater base 251 so that the processtube 203 is installed vertically. The reaction container is formed bythe process tube 203 and the manifold 209.

A nozzle 230 as a gas supply part is connected to a seal cap 219 (to bedescribed later) such that the nozzle 230 communicates with an interiorof the process chamber 201. A gas supply pipe 232 is connected to thenozzle 230. A process gas source or an inert gas source (not shown) isconnected to an upper stream side of the gas supply pipe 232, which isan opposite side of where the gas supply pipe 232 is connected to thenozzle 230, with a mass flow controller (MFC) 241 as a gas flow ratecontrol unit interposed therebetween. A gas flow rate control part (gasflow rate controller) 235 is electrically connected to the MFC 241 suchthat a supplied gas flow rate can be controlled to be a desired amountat a desired timing.

An exhaust pipe 231 for discharging atmosphere from the interior of theprocess chamber 201 is installed in the manifold 209. The exhaust pipe231 is disposed at a lower end portion of a container-like space formedby a gap between the inner tube 204 and the outer tube 205, andcommunicates with the container-like space. It is configured so that anevacuation device 246, such as a vacuum pump, is connected to a lowerstream side of the exhaust pipe 231, which is an opposite side of wherethe exhaust pipe 231 is connected to the manifold 209, with a pressuresensor 245 as a pressure detector and a pressure adjusting device 242interposed therebetween, in order to perform evacuation such thatpressure within the process chamber 201 has a predetermined pressurelevel (vacuum degree). A pressure control part 236 (a pressurecontroller) is electrically connected to the pressure adjusting device242 and the pressure sensor 245 and is configured to control thepressure within the process chamber 201 to be a desired pressure levelat a desired timing by the pressure adjusting device 242 based onpressure detected by the pressure sensor 245.

The seal cap 219 is installed as a lid member of a furnace port belowthe manifold 209 to air-tightly seal an opening of the lower end portionof the manifold 209. The seal cap 219 is configured to be in contactwith the lower end portion of the manifold 209 from below in a verticaldirection. The seal cap 219 may be, for example, made of a metal such asstainless steel or the like, and has a disk shape. An O-ring 220 b,which is a sealing member in contact with the lower end portion of themanifold 209, is installed at an upper surface of the seal cap 219. Arotary mechanism 254 configured to rotate the boat 217 is installed atthe opposite side of the seal cap 219 from the process chamber 201. Arotary shaft 255 of the rotary mechanism 254 is connected to the boat217 through the seal cap 219. The rotary shaft 255 is configured torotate the wafers 200 by rotating the boat 217. The seal cap 219 isconfigured to be vertically elevated and lowered by a boat elevator 115,which is an elevation mechanism installed vertically outside the processtube 203, whereby the boat 217 can be loaded into or unloaded from theprocess chamber 201. A driving control part (driving controller) 237 iselectrically connected to the rotary mechanism 254 and the boat elevator115 to control a desired operation to occur at a desired timing.

The boat 217 is formed of a heat resistant material such as, forexample, quartz or silicon carbide, and is configured to support aplurality of sheets of wafers 200, which are horizontally stacked inmultiple stages with the centers thereof aligned with one another alongan axial direction. Further, a plurality of sheets of insulating plates216 as insulating members, which have a disk shape and are formed of aheat resistant material such as, for example, quartz or silicon carbide,are disposed at the lower portion of the boat 217 to be horizontallystacked in multiple stages. The insulating plates 216 prevent heat ofthe heater 206 from being transferred to the manifold 209.

A temperature sensor 263, which is a temperature detector, is installedwithin the process tube 203. A temperature control part 238 iselectrically connected to the heater 206 and the temperature sensor 263.The temperature control part 238 controls the supply of electric powerto the heater 206 (specifically, a heater line 208) based on temperatureinformation detected by the temperature sensor 263. Accordingly, thewafers 200 are heated from outer edges thereof to have a temperatureincreased to a desired level. Further, the heater 206 also has a coolingfunction to cool the heated wafers 200 by a cooling gas, and this willbe described later.

The gas flow rate control part 235, the pressure control part 236, thedriving control part 237, and the temperature control part 238 are alsoconfigured with operating parts and input/output parts and areelectrically connected to a main control part (main controller) 239 forcontrolling the entire substrate processing apparatus. The gas flowcontrol part 235, the pressure control part 236, the driving controlpart 237, the temperature control part 238, and the main control part239 constitute a controller 240.

Hereinafter, a method of forming a thin film on each wafer 200 through achemical vapor deposition (CVD) as a process in manufacturing asemiconductor device in which the processing furnace 202 having theforegoing configuration is used will be described. Further, in thefollowing descriptions, operations of the respective parts constitutingthe substrate processing apparatus are controlled by the controller 240.

When the plurality of sheets of wafers 200 are charged on the boat 217(wafer charging), as illustrated in FIG. 1, the boat 217 supporting theplurality of sheets of wafers 200 is raised by the boat elevator 115 tobe loaded into the process chamber 201 (boat loading). In this state,the seal cap 219 seals the lower end portion of the manifold 209 throughthe O-ring 220 b.

The inside of the process chamber 201 is vacuum-evacuated by theevacuation device 246 to have a desired pressure (vacuum degree). Here,the interior pressure within the process chamber 201 is measured by thepressure sensor 245. The pressure adjusting device 242 isfeedback-controlled based on the measured pressure. Furthermore, theinside of the process chamber 201 is heated by the heater 206 to have adesired temperature. Here, in order for the in side of the processchamber 201 to have a desired temperature distribution, the supply ofelectric power to the heater 206 is feedback-controlled based on thetemperature information detected by the temperature sensor 263.Subsequently, the boat 217 is rotated by the rotary mechanism 254,whereby the wafers 200 are rotated.

Subsequently, a gas that has been supplied from the process gas sourceand controlled by the MFC 241 to have a desired flow rate flows throughthe gas supply pipe 232 and is supplied into the process chamber 201 viathe nozzle 230. The supplied gas ascends within the process chamber 201and flow out from the opening of the upper end portion of the inner tube204 to the container-like space so as to be discharged from the exhaustpipe 231. When the gas passes through the inside of the process chamber201, it comes into contact with a surface of each wafer 200. At thistime, a thin film is deposited on the surface of each wafer 200 by athermal CVD reaction.

When a preset processing period of time has lapsed, an inert gas issupplied from an inert gas source, and thus, the interior atmosphere ofthe process chamber 201 is substituted with the inert gas and theinternal pressure of the process chamber 201 is also returned to anormal pressure. Each wafer 200 is quenched to a desired temperature bythe cooling function of the heater 206.

Thereafter, the seal cap 219 is lowered down by the boat elevator 115 toopen the lower end portion of the manifold 209. The processed wafers 200supported on the boat 217 are unloaded out of the process tube 203through the lower end portion of the manifold 209 (boat unloading).Thereafter, the processed wafers 200 are discharged from the boat 217(wafer discharging)

Further, in this example for processing the wafers in the processingfurnace of this embodiment, for example, an SiN film (silicon nitridefilm) may be formed, for example, with SiH₂Cl₂ and NH₃ as film forminggases under processing conditions of a processing temperature rangingfrom 400 to 800 degrees C., a processing pressure ranging from 1 to 50Torr, a gas supply flow rate of the SiH₂Cl₂ ranging from 0.02 to 0.30slm, and a gas supply flow rate of the NH₃ ranging from 0.1 to 2.0 slm.In addition, a poly-silicon film may also be formed, for example, withSiH4 as a film forming gas under processing conditions of a processingtemperature ranging from 350 to 700 degrees C., a processing pressureranging from 1 to 50 Torr, and a gas supply flow rate of the SiH4ranging from 0.01 to 1.20 slm. The wafers 200 may be processed byconsistently maintaining each processing condition at a certain valuewithin each range.

The heater 206 will be described in detail. The heater 206 may include aside wall heat insulator 250 (a side wall heat insulating member)installed outside the process tube 203, a ceiling heat insulator (aceiling insulating member) 252 installed above the side wall heatinsulator 250, a heater line (a heating member) 208 installed in theinner wall of the side wall heat insulator 250, and a cooling gas flowpath 256 installed between the process tube 203 and the side wall heatinsulator 250. At least one inlet port 258 may be installed in thevicinity of the lower end portion of the side wall heat insulator 250.The flow path 256 formed within the heater 206 may communicate with theoutside of the heater 206 through the inlet port 258.

The ceiling heat insulator 252 may have a hollow gas-flow path 260installed therein. The gas-flow path 260 may communicate with the flowpath 256 and also may communicate with an exhaust pipe 56 connected toan outer circumferential surface (specifically, a lateral surface) ofthe ceiling heat insulator 252. A damper 54 that can be opened andclosed may be installed in the exhaust pipe 56. A radiator 58 and a fan60 may be connected to a lower stream side of the damper 54. When thewafers 200 are heated by the heater 206, the damper 54 may be closed andthe fan 60 may not operate. Meanwhile, when the wafers 200 are cooled bythe cooling function of the heater 206, the damper 54 may be opened andthe fan 60 may operate to absorb the cooling gas.

Here, the cooling function of the heater 206 will be described. Theheater 206 may flow the cooling gas (for example, air or an inert gas)to the flow path 256 to cool the wafers 200, starting from outer edgesthereof. The cooling gas may be supplied to the flow path 256 of theheater 206 through the inlet port 258 from the outside and may passthrough the flow path 256 upwardly. Then, the cooling gas may bedischarged to the outside of the substrate processing apparatus 1through the gas-flow path 260 installed within the ceiling heatinsulator 252, the exhaust pipe 56 communicating with the gas-flow path260, the radiator 58, and the fan 60. Further, an operation of the fan60 may be controlled by the controller 240 (for example, the temperaturecontrol part 238 therein). In FIG. 1, although the inlet port 258 isinstalled in a lower portion of the side wall heat insulator 250, theinlet port 258 may be installed in the vicinity of the upper end portionor in a middle position of the side wall heat insulator 250. In thiscase, for example, it is preferable to allow the cooling gas to passthrough the inside of the side wall heat insulator 250 and be suppliedtoward a lower side of the flow path 256 so as to be spread to theentirety of the flow path 256.

Hereinafter, a characteristic structure of the ceiling heat insulator252 in the present disclosure will be described in detail. FIG. 2 is aperspective view schematically illustrating the heater 206. Further,FIG. 3 is an enlarged cross-sectional view of the ceiling heat insulator252.

The ceiling heat insulator 252 may be formed of a highly heat resistantmaterial (for example, ceramics or the like). As illustrated in FIG. 2,the ceiling heat insulator 252 has a circular shape when viewed from aplan view. A plurality of exhaust port 262 may be formed to be adjacenton the outer circumferential surface (specifically, on the lateralsurface) of the ceiling heat insulator 252. Each of the plurality ofexhaust port 262 may communicate with the respective gas-flow path 260.Also, the inlet port 258 is omitted in FIG. 2.

As illustrated in FIGS. 2 and 3, the ceiling heat insulator 252 includesa plurality of members (specifically, two members 252 a and 252 b)stacked in a vertical direction. Hereinafter, the lower member 252 awill be referred to as a “lower heat insulator” and the upper member 252b will be referred to as an “upper heat insulator”.

FIG. 4 is a top view of the lower heat insulator 252 a and FIG. 5 is abottom view of the lower heat insulator 252 a. FIG. 6 is across-sectional view taken along line A-A of FIG. 4. As illustrated inFIGS. 4 to 6, the lower heat insulator 252 a may include a plurality ofconcave portions (specifically, two concave portions 252 a 1) formed onan upper surface thereof. The concave portions 252 a 1 may also bereferred to as a counterbore portion having side walls on acircumference thereof. The two concave portions 252 a 1 may be formed tobe symmetrical with respect to a certain central line on a horizontalplane of the ceiling heat insulator 252 therebetween. A supply port 252a 2 communicating with the flow path 256 of the heater 206 may be formedon a lower portion of each of the concave portions 252 a 1. The concaveportions 252 a 1 may be formed in a position outside the outer edges ofthe wafers 200 accommodated in the process tube 203, when viewed from aplan view. Thus, the supply ports 252 a 2 may be also formed in aposition outside the outer edges of the wafers 200, when viewed from aplan view. In addition, a plurality of supply ports 252 a 2 may beformed on a concentric circle having its center on a center of theceiling heat insulator 252 to be spaced apart from one another as muchas possible. In the illustrated example, the two supply ports 252 a 2are formed to be spaced apart by about 180° on the concentric circle.

Specifically, the concave portions 252 a 1 may be formed to respectivelyhave a circular arc shape, having its center on a central portion of thelower heat insulator 252 a. A lower heat insulating wall 252 a 3 may beformed between the two concave portions 252 a 1 to divide themspatially. Further, each concave portion 252 a 1 may have a taperedportion 252 a 4 at a side that is close to the center of the ceilingheat insulator 252 so that a depth of the concave portion 252 a 1 getsreduced toward the center of the ceiling heat insulator 252. Also, ineach concave portion 252 a 1, a cutout portion 252 a 6 may be formed ona side wall at an outer edge adjacent to the lower heat insulating wall252 a 3.

An annular recess portion 252 a 7 may be formed at an inner side (at acentral side of the lower heat insulator 252 a) of the concave portion252 a 1 on the upper surface of the lower heat insulator 252 a. Further,on a bottom surface of the lower heat insulator 252 a, a plurality ofgroove portions 252 a 8 may be formed radially from the central portionof the lower heat insulator 252 a. The groove portions 252 a 8 aregrooves for alleviating stress. The groove portions 252 a 8 mayalleviate the stress generated when the ceiling heat insulator 252 isheated to prevent damage to the ceiling heat insulator 252. At least oneof the groove portions 252 a 8 may be connected to the supply ports 252a 2. At least one of the groove portions 252 a 8 may be configured toreach the outer circumference of the lower heat insulator 252 a. Atleast one of the groove portions 252 a 8 may be configured not to reachthe outer circumference of the lower heat insulator 252 a.

FIG. 7 is a top view of the upper heat insulator 252 b. FIG. 8 is abottom view of the upper heat insulator 252 b. Further, FIG. 9 is across-sectional view taken along line B-B of FIG. 8. As illustrated inFIGS. 7 to 9, the upper heat insulator 252 b includes a plurality ofconcave portions (specifically, two concave portions 252 b 1) formed ona bottom surface thereof. The concave portions 252 b 1 may also bereferred to as a counterbore portion having side walls on acircumference thereof. The two concave portions 252 b 1 may be formed tobe symmetrical with respect to a certain central line on a horizontalplane of the ceiling heat insulator 252 therebetween. The concaveportions 252 b 1 may be formed in a position outside the outer edges ofthe wafers 200 accommodated in the process tube 203, when viewed from aplan view.

Specifically, the concave portions 252 b 1 may be formed to respectivelyhave a circular arc shape, having its center on a central portion of theupper heat insulator 252 b. An upper heat insulating wall 252 b 3 may beformed between the two concave portions 252 b 1 to divide themspatially. Further, each concave portion 251 b 1 may have a taperedportion 252 b 4 at a side that is close to the center of the ceilingheat insulator 252 so that a depth of the concave portion 252 b 1 getsreduced toward the center of the ceiling heat insulator 252. Also, ineach concave portion 252 b 1, a cutout portion 252 b 6 may be formed ona side wall at an outer edge adjacent to the upper heat insulating wall252 b 3. Further, on a bottom surface of the upper heat insulator 252 b,an annular protrusion 252 b 7 may be formed in an inner side of theconcave portion 252 b 1.

The concave portions 252 a 1 of the lower heat insulator 252 a and theconcave portions 252 b 1 of the upper heat insulator 252 b may be formedto be symmetrical or substantially symmetrical in shape when the uppersurface of the lower heat insulator 252 a and the bottom surface of theupper heat insulator 252 b overlap with each other, except that theconcave portions 252 a 1 of the lower heat insulator 252 a include thesupply ports 252 a 2.

As illustrated in FIG. 3, the lower heat insulator 252 a and the upperheat insulator 252 b may overlap with each other so that the concaveportions 252 a 1 of the lower heat insulator 252 a and the concaveportions 252 b 1 of the upper heat insulator 252 b are disposed in afacing manner to form two gas-flow paths 260. As described above, sinceeach of the concave portions 252 a 1 and 252 b 1 has a circular arcshape having its center on the central portion of the insulators 252 aand 252 b, each gas-flow path 260 is also formed to have a circular arcshape having its center on the central portion of the ceiling heatinsulator 252.

Since the ceiling heat insulator 252 includes the gas-flow paths 260installed therein, respectively having a circular arc shape having thecenter on the central portion of the ceiling heat insulator 252, athickness T2 of an outer edge side is smaller than a thickness T1 of acenter side (in FIG. 3). Here, the “thickness” of the ceiling heatinsulator 252 indicates a thickness of the ceiling heat insulator in avertical direction. In particular, as indicated by T2 in FIG. 3, thethickness of the ceiling heat insulator 252 indicates a consecutivelength along which the member extends from the bottom surface toward theupper surface. If a space such as the gas-flow paths 260 is presentwithin the ceiling heat insulator 252, a sum of the thicknesses of themembers of the lower side and the upper side of the corresponding spacemay be considered as the “thickness”. As described above, since thethickness T2 at the outer edge is smaller than the thickness T1 at thecenter side, a solid cross-sectional area (the area excluding the hollowportion in a vertical cross-section) of the ceiling heat insulator 252in the outer edge is smaller than that in the center side. FIGS. 1 and 3include the cross-section views taken along line A-A of FIG. 4 or takenalong line B-B of FIG. 8. FIGS. 1 and 3 include the cross-section of thesubstrate processing apparatus 1 and the cross-section of the ceilingheat insulator 252, respectively.

Since the lower insulating wall 252 a 3 and the upper insulating wall252 b 3 are installed between the gas-flow paths 260, the gas-flow paths260 may be spatially separated within the ceiling heat insulator 252.Further, the gas-flow paths 260 may be formed as spaces of circular arcshapes having their center at the central portion of the ceiling heatinsulator 252 by the concave portions 252 a 1 and 252 b 1 and may beinstalled in a position outside the wafers 200 when viewed from a planview. Also, due to the tapered portion 252 a 4 of the lower heatinsulator 252 a and the tapered portion 252 b 4 of the upper heatinsulator 252 b, the gas-flow paths 260 may be formed to have across-sectional area reduced in a direction toward the center side ofthe ceiling heat insulator 252. In other words, the ceiling heatinsulator 252 is formed to have a solid cross-sectional area that isincreased toward the center side thereof.

Further, when the lower heat insulator 252 a and the upper heatinsulator 252 b overlap with each other, the protrusion portions 252 b 7of the upper heat insulator 252 b may be fitted to the recess portions252 a 7 of the lower heat insulator 252 a. Accordingly, the lower heatinsulator 252 a and the upper heat insulator 252 b may be adjusted andfixed in their positions. In order to fix the lower heat insulator 252 aand the upper heat insulator 252 b, for example, an adhesive may also beused additionally.

Also, as the lower heat insulator 252 a and the upper heat insulator 252b overlap with each other, the cutout portion 252 a 6 of the lower heatinsulator 252 a and the cutout portion 252 b 6 of the upper heatinsulator are disposed to face each other, forming the exhaust ports 262in the gas-flow paths 260, respectively, as described above. The exhaustports 262 installed in the gas-flow paths 260 may be adjacent with thelower insulating wall 252 a 3 and the upper insulating wall 25 b 3interposed therebetween (see FIG. 2).

FIG. 10 is a view illustrating a flow of a cooling gas within theceiling heat insulator 252. As illustrated in FIG. 10, the cooling gassupplied to the ceiling heat insulator 252 through the supply ports 252a 2 in the gas-flow paths 260 may fill the gas-flow paths 260 and mayflow to the exhaust pipe 56 through the exhaust ports 262 in thegas-flow paths 260 so as to be discharged to the outside of thesubstrate processing apparatus 1.

Hereinafter, temperature characteristics of the wafer 200 when theheater 206 is used will be described. FIG. 11 is a view illustrating atemperature distribution in a cross-section of the wafer 200 when theheater 206 is used. Further, FIG. 12 is a view illustrating atemperature transition of the wafer 200 when the heater is used.

Here, for the convenience of understanding, wafer temperaturecharacteristics when a different type of heater is used will bedescribed.

FIG. 13 is a schematic view illustrating an example of a heater withouta cooling function by a cooling gas according to an embodiment of thepresent disclosure. Further, FIG. 14 is a view illustrating atemperature distribution in a cross-section of a wafer when the heaterof FIG. 13 is used. As described above, the wafer within the processtube is heated by the heater disposed outside of the process tube. Thus,in the example of the heater illustrated in FIG. 13, the temperature ofthe outer edge portion of the wafer gets higher, compared with a centralportion thereof, as described in FIG. 14. In FIG. 14, a temperaturedifference between the central portion and the outer edge portions ofthe wafer is denoted by Δt.

FIG. 15 is a view illustrating a temperature transition of a wafer whenthe heater of FIG. 13 is used. As illustrated in FIG. 15, in the case ofheating up the wafer, due to the temperature distribution tendencyillustrated in FIG. 14, the temperature of the outer edge portion of thewafer first reaches a target temperature and the temperature of thecentral portion of the wafer reaches the target temperature later. It isdesirable to reduce a temperature rise delay time Td1 because itdegrades throughput of wafer processing.

FIG. 16 is a schematic view illustrating an example of a heater having acooling function using a cooling gas. Unlike the heater 206 illustratedin FIGS. 1 to 10, the heater illustrated in FIG. 16 has a supply port ofa cooling gas formed in a central portion of the ceiling heat insulator.

FIG. 17 is a view illustrating a temperature distribution in across-section of a wafer when the heater of FIG. 16 is used. In theheater illustrated in FIG. 16, since the supply port of the cooling gasis formed in the central portion of the ceiling heat insulator, a solidcross-sectional area (or a thickness) of the ceiling heat insulator inthe vicinity of the central portion thereof is smaller than that in theouter edge portion (i.e., thickness T1 of the central portion<thicknessT2 of the outer edge portion). Thus, heat insulating properties of thevicinity of the central portion of the ceiling heat insulator are lowerthan those of the outer edge portion of the ceiling heat insulator sothat a temperature difference (Δt) between the central portion and theouter edge portion of the wafer further increases, as illustrated inFIG. 17. Thus, the temperature rise delay time Td1 is also highly likelyto increase. This tendency increases as the wafer is loaded in a higherposition of the boat. Also, when the wafer is heated by the heater, thedamper within the exhaust pipe is closed so that the cooling gas stayswithin the heater, as described above.

FIG. 18 is a schematic view illustrating another example of a heaterhaving a cooling function using a cooling gas. The heater illustrated inFIG. 18 is configured to supply a cooling gas from an annular slit byhermetically sealing the central portion of the supply port of thecooling gas in the ceiling heat insulator of the heater illustrated inFIG. 16.

FIG. 19 is a view illustrating a temperature distribution in across-section of a wafer when the heater of FIG. 18 is used. Further,FIG. 20 is a view illustrating a temperature transition of a wafer whenthe heater of FIG. 18 is used. In the heater illustrated in FIG. 18,heat insulating properties of the vicinity of the central portion of theceiling heat insulator are improved, but convection of the cooling gasmay be generated through the supply port of the cooling gas above thewafer. When convection of the cooling gas is generated above the wafer,as illustrated in FIG. 19, in addition a temperature difference (Δt)between the outer edge portion and the central portion of the wafer thatstill remains, a temperature difference between the outer edges portionsof the wafer occurs. Thus, as illustrated in FIG. 20, the temperaturerise delay time Td1 does not decrease.

In contrast, in the heater 206 illustrated in FIGS. 1 to 10, since thegas-flow paths 260, as spaces of a circular arc shape having theircenter at the center portion of the ceiling heat insulator 252, areinstalled to allow the cooling gas to pass therethrough, the solidcross-sectional area (the thickness) of the ceiling heat insulator 252in the outer edge side is smaller than that in the center side of theceiling heat insulator 252 so that heat insulating properties of theceiling heat insulator 252 are lower in the outer edge side than thosein the center side. Accordingly, the tendency of the temperaturedistribution illustrated in FIG. 14 generated as the wafer 200 is heatedstarting from the outer edge side thereof, can be canceled out. Thus, asillustrated in FIG. 11, the in-plane temperature distribution of thewafer 200 is substantially uniform from the center portion to the outeredge and the in-plane temperature uniformity of the wafer 200 isenhanced. Further, accordingly, as illustrated in FIG. 12, thetemperature rise delay time Td1 can be reduced, compared with theexamples illustrated in FIGS. 13 to 20.

Also, in the gas-flow paths 260, the supply ports 252 a 2 allowing thecooling gas to be supplied therethrough are formed in an outer positionof the wafer 200 when viewed from a plan view. Thus, even thoughconvection is generated in the cooling gas supplied to the gas-flowpaths 260 from the supply ports 252 a 2, since the outer edge side ofthe wafer 200 is cooled, the temperature at the center side of the waferis prevented from being lowered so that the in-plane temperatureuniformity is prevented from being negative effect. Further, even thoughheat insulating properties of the portion where the supply ports 252 a 2are formed are most degraded, the in-plane temperature uniformity is notdamaged in that the portion where the supply ports 252 a 2 are formed ispositioned outside the outer edge portion of the wafer 200, when viewedfrom a plan view, not being positioned immediately above the wafer 200,and the wafer 200 is heated, starting from the outer edge side thereof,by the heater 206.

Similarly, since the gas-flow paths 260 are installed in the positionoutside the wafer 200 when viewed from a plan view, the temperature ofthe center side of the wafer is not lowered by the cooling gas stayingin the gas-flow path 260.

Further, since the plurality of gas-flow paths 260 are installed and theinsulating walls 252 a 3 and 252 b 3 are installed between the gas-flowpaths 260, heat exchange between the gas-flow paths 260 may berestrained so that convection of the cooling gas staying in the gas-flowpaths 260 can be restrained.

Further, since each of the plurality of gas-flow paths 260 has therespective supply port 252 a 2 and the respective exhaust port 262, thesupply ports 252 a 2 are not connected via the gas-flow paths 260 sothat the convection of a cooling gas may be more effectively restrained.

Further, since the gas-flow paths 260 are formed such that across-sectional area thereof is reduced toward the center side of theceiling heat insulator 252 (in other words, the solid cross-sectionalarea of the ceiling heat insulator 252 increases toward the centerside), the heat insulating properties of the ceiling heat insulator 252are gradually changed (i.e., enhanced) toward the center side of theceiling heat insulator 252. Thus, a temperature distribution of thewafer 200 can become more effectively uniformized and a temperaturegradient can become gentle.

Further, since the plurality of supply ports 252 a 2 are formed to bespaced apart from one another as much as possible on the concentriccircle having its center on the center portion of the ceiling heatinsulator 252, portions of the ceiling heat insulator 252 where heatinsulating properties thereof are most degraded are evenly distributed,negative effect on the in-plane temperature uniformity of the wafer 200can be further effectively restrained.

Further, since the exhaust ports 262 are formed to be adjacent to eachother on the lateral surface of the ceiling heat insulator 252, theexhaust pipe 56 can be formed as a single system to simplify an exhaustconfiguration. Also, since the exhaust ports 262 are formed on thelateral surface, an overall height can be lowered, compared with a casein which the exhaust mechanism is installed above the heater 206.

Since the supply ports 252 a 2 are formed in the gas-flow paths 260,heat insulating properties in the portions of the outer edge side of theceiling heat insulator 252 where the supply ports 252 a 2 are formed aredegraded. In addition, even in the outer edge side of the ceiling heatinsulator 252, in the portions where the insulating walls 252 a 3 and252 b 3 are installed, heat insulating properties are not degraded.However, the difference in such local heat insulating properties andin-plane temperature variations of the wafer 200 accompanied therewithare symmetrical with respect to a certain center line of the wafer 200and thus, can become uniformized by rotating the wafer 200 by the rotarymechanism 254. Accordingly, a desired in-plane temperature distributioncan be achieved by adjusting the size of the supply ports 252 a 2 or thewidth of the insulating walls 252 a 3 and 252 b 3.

In one embodiment, the thicknesses of each part of the ceiling heatinsulator 252, the size of the supply ports 252 a 2, and the widths ofthe insulating walls 252 a 3 and 252 b 3 may be set to achieve atemperature distribution, as illustrated in FIG. 11, where a temperatureof the center portion of the wafer 200 is slightly higher than that ofthe outer edge portion thereof when the wafer 200 is rotated by therotary mechanism 254. If a process gas is supplied from the outer edgeside of the wafer 200, the process gas is first consumed at the outeredge side so that a film thickness of the center side of the wafer 200may be reduced. In such case, however, by forming the temperaturegradient as illustrated in FIG. 11, deposition rates at the center sideand at the outer edge side of the wafer 200 become equal to enhance filmthickness uniformity.

Hereinafter, modifications of the present disclosure will be described.Specifically, since only a configuration of a ceiling heat insulator ismodified from the embodiment described above, only explanation about theceiling heat insulator will be described.

FIG. 21 is a cross-sectional view illustrating a first modification of aceiling heat insulator. As illustrated in FIG. 21, a ceiling heatinsulator 300 according to the first modification includes a lower heatinsulator 300 a and an upper heat insulator 300 b. Gas-flow paths 360are installed in the ceiling heat insulator 300. Here, the gas-flowpaths 360 are formed only with concave portions 300 a 1 formed in thelower heat insulator 300 a. Thus, exhaust ports of a cooling gas arealso formed only at the lower heat insulator 300 a. The gas-flow paths360 are installed outside the outer edge portion of the wafer, whenviewed from a plan view. The ceiling heat insulator 300 may also providethe same effect as that described above.

FIG. 22 is a cross-sectional view illustrating a second modification ofa ceiling heat insulator. As illustrated in FIG. 22, a ceiling heatinsulator 400 according to the second modification includes a lower heatinsulator 400 a and an upper heat insulator 400 b. Gas-flow paths 460are installed in the ceiling heat insulator 400. Here, the gas-flowpaths 460 are formed only with concave portions 400 b 1 formed in theupper heat insulator 400 b. Thus, exhaust ports of a cooling gas arealso formed only at the upper heat insulator 400 b. The gas-flow paths460 are installed outside the outer edge portion of the wafer, whenviewed from a plan view. The ceiling heat insulator 400 may also providethe same effect as that of the ceiling heat insulator described above.

FIG. 23 is a cross-sectional view illustrating a third modification of aceiling heat insulator. As illustrated in FIG. 23, in a ceiling heatinsulator 500 according to the third modification, a tapered portion 500a 4 installed in a concave portion 500 a 1 of a lower heat insulator 500a and a tapered portion 500 b 4 installed in a concave portion 500 b 1of an upper heat insulator 500 b are continuous. Even though the taperedportions are configured in this manner, a thickness of the ceiling heatinsulator 500 (heat insulating properties thereof) can be continuouslychanged from the center side to an outer edge side. Further, the concaveportion 500 a 1 and the concave portion 500 b 1 (and the gas-flow paths560 formed thereby) are formed outside the outer edge portion of thewafer when viewed from a plan view. The ceiling heat insulator 500 mayalso provide the same effect as that of the ceiling heat insulatordescribed above.

FIG. 24 is a cross-sectional view illustrating a fourth modification ofa ceiling heat insulator. As illustrated in FIG. 24, in a ceiling heatinsulator 600 according to the fourth modification, exhaust ports 662communicating with respective gas-flow paths 660 are formed in an upperheat insulator 600 b. Further, the exhaust ports 662 are formed on anouterside of an outer edge portion of the wafer when viewed from a planview. This modification may also provide the same effect as that of theceiling heat insulator described above, except that two exhaust pipesystems (not shown) are required and an overall height of a heaterincluding the exhaust pipes increases.

FIG. 25 is a plan view of a lower heat insulator illustrating the fourthmodification of the ceiling heat insulator and FIG. 26 is a bottom viewof the lower heat insulator representing the fourth modification of theceiling heat insulator. As illustrated, in a ceiling heat insulator 700according to the fourth modification, a plurality of supply ports 700 a2 are formed in each of concave portions 700 a 1 of a lower heatinsulator 700 a. In the illustrated example, three supply ports 700 a 2are formed in each of two concave portions 700 a 1. The supply ports 700a 2 are disposed on a concentric circle having its center on a centerportion of the ceiling heat insulator 700 to be spaced apart from oneanother as much as possible, by an interval of 60°. Further, the concaveportion 700 a 1 and the concave portion 700 b 1 (and the gas-flow pathsformed thereby) are formed outside the outer edge portion of the waferwhen viewed from a plan view. Similarly, each supply port 700 a 2 isalso formed outside the outer edge portion of the wafer when viewed froma plan view. The fourth modification may also provide the same effect asthat of the ceiling heat insulator described above. In the fourthmodification, since the plurality of supply ports 700 a 2 are formed inthe single concave portion 700 a 1, convection may be generated betweenthe supply ports 700 a 2. However, since all the supply ports 700 a 2are formed outside the outer edge portion of the wafer when viewed froma plan view, a resulting influence on the temperature distribution ofthe wafer is smaller than the case of the configuration of the heaterillustrated in FIG. 18.

FIG. 27 is a plan view of a lower heat insulator illustrating a fifthmodification of a ceiling heat insulator and FIG. 28 is a bottom view ofthe lower heat insulator illustrating the fifth modification of theceiling heat insulator. FIG. 29 is a bottom view of an upper heatinsulator illustrating the fifth modification of the ceiling heatinsulator. As illustrated, in a ceiling heat insulator 800 according tothe fifth modification, four concave portions 800 a 1 respectivelyhaving a circular arc shape are formed in a lower heat insulator 800 a.In each concave portion 800 a 1, a supply port 800 a 2 and cutoutportions 800 a 6 are formed. Further, four concave portions 800 b 1having a circular arc shape are also formed in an upper heat insulator800 b and cutout portions 800 b 6 are formed in each concave portion 800b 1. Two cutout portions 800 a 6 are disposed to be adjacent on thelateral surface of the ceiling heat insulator 800. Similarly, two cutoutportions 800 b 6 are also disposed to be adjacent on the lateral surfaceof the ceiling heat insulator 800. Further, the concave portions 800 a 1and the concave portions 800 b 1 (and the gas-flow paths formed thereby)are formed outside the outer edge portion of the wafer when viewed froma plan view. Similarly, each supply port 800 a 2 is also formed outsidethe outer edge portion of the wafer when viewed from a plan view. Thismodification may also provide the same effect as that of the ceilingheat insulator described above, except that a plurality of exhaust pipesystems (not shown) are required. Further, even though in FIG. 27, twocutout portions 800 b 6 are formed in each concave portion 800 b 1, itis still possible to have only one cutout portion 800 b 6 in eachconcave portion 800 b 1.

Further, a ceiling heat insulator may also be formed by combining themodifications described above. Also, the number of gas-flow paths,supply ports, and exhaust ports are not limited to the foregoingexamples, but may be modified depending on the size of the ceiling heatinsulator, or the like.

Aspects of Present Disclosure

The present disclosure will be further stated with the followingsupplementary aspects.

[Supplementary Note 1]

A substrate processing apparatus, including:

-   -   a reaction container configured to accommodate a substrate; and    -   a heating apparatus having a side wall heat insulator located at        an outer circumference of the reaction container, a ceiling heat        insulator located above the side wall heat insulator, a heating        element located on an inner wall of the side wall heat        insulator, and a cooling gas flow path located between the        reaction container and the side wall heat insulator,    -   wherein the ceiling heat insulator is configured to include a        gas-flow path located therein to allow a cooling gas to pass        therethrough so that the ceiling heat insulator has a solid        cross-sectional area in an outer edge side of the ceiling heat        insulator that is smaller than that in a center side of the        ceiling heat insulator.        [Supplementary Note 2]

The substrate processing apparatus of Supplementary Note 1,

-   -   wherein the gas-flow path includes a space of a circular arc        shape having its center at a central portion of the ceiling heat        insulator.        [Supplementary Note 3]

The substrate processing apparatus of Supplementary Note 1 or 2,

-   -   wherein the gas-flow path includes a supply port configured to        supply the cooling gas and an exhaust port configured to        discharge the supplied cooling gas, and    -   wherein the supply port is located in a position outside the        substrate when viewed from a plan view.        [Supplementary Note 4]

The substrate processing apparatus of any one of Supplementary Notes 1to 3,

-   -   wherein the gas-flow path is located in a position outside the        substrate when viewed from a plan view.        [Supplementary Note 5]

The substrate processing apparatus of any one of Supplementary Notes 1to 4,

-   -   wherein the gas-flow path has a cross-sectional area that gets        reduced toward a center side of the ceiling heat insulator.        [Supplementary Note 6]

The substrate processing apparatus of any one of Supplementary Notes 1to 5,

-   -   wherein there are a plurality of gas-flow paths having one or        more insulating walls located therebetween.        [Supplementary Note 7]

The substrate processing apparatus of Supplementary Note 6,

-   -   wherein each of the plurality of gas-flow paths includes a        supply port configured to supply the cooling gas and an exhaust        port configured to discharge the supplied cooling gas.        [Supplementary Note 8]

The substrate processing apparatus of Supplementary Note 7,

-   -   wherein the supply ports included in the plurality of gas-flow        paths are formed to be spaced apart from one another to the        maximum on a concentric circle having its center at a central        portion of the ceiling heat insulator.        [Supplementary Note 9]

The substrate processing apparatus of Supplementary Note 7 or 8,

-   -   wherein the exhaust ports included in the plurality of gas-flow        paths are formed to be adjacent to one another on a lateral        surface of the ceiling heat insulator.        [Supplementary Note 10]

A substrate processing apparatus, including:

-   -   a reaction container configured to accommodate a substrate; and    -   a heating apparatus having a side wall heat insulator located at        an outer circumference of the reaction container, a ceiling heat        insulator located above the side wall heat insulator, a heating        element located on an inner wall of the side wall heat        insulator, and a cooling gas flow path located between the        reaction container and the side wall heat insulator,    -   wherein the ceiling heat insulator is configured to include a        gas-flow path having a space of a circular arc shape having its        center at a central portion of the ceiling heat insulator and        allowing a cooling gas to pass therethrough.        [Supplementary Note 11]

A heating apparatus, including:

-   -   a side wall heat insulator located at an outer circumference of        a reaction container;    -   a ceiling heat insulator located above the side wall heat        insulator;    -   a heating element located on an inner wall of the side wall heat        insulator; and    -   a cooling gas flow path located between the reaction container        and the side wall heat insulator,    -   wherein the ceiling heat insulator is configured to include a        gas-flow path located therein to allow a cooling gas to pass        therethrough so that the ceiling heat insulator has a solid        cross-sectional area in an outer edge side of the ceiling heat        insulator that is smaller than that in a center side of the        ceiling heat insulator.        [Supplementary Note 12]

A heating apparatus, including:

-   -   a side wall heat insulator located at an outer circumference of        a reaction container;    -   a ceiling heat insulator located above the side wall heat        insulator;    -   a heating element located in on inner wall of the side wall heat        insulator; and    -   a cooling gas flow path located between the reaction container        and the side wall heat insulator,    -   wherein the ceiling heat insulator is configured to include a        gas-flow path having a space of a circular arc shape having its        center at a central portion of the ceiling heat insulator and        allowing a cooling gas to pass therethrough.        [Supplementary Note 13]

A ceiling heat insulator,

-   -   wherein the ceiling heat insulator is located above a side wall        heat insulator of a heating apparatus for a substrate processing        apparatus, and    -   wherein the ceiling heat insulator includes a gas-flow path        located therein to allow a cooling gas to pass therethrough so        that the ceiling heat insulator has a solid cross-sectional area        in an outer edge side of the ceiling heat insulator that is        smaller than that in a center side of the ceiling heat        insulator.        [Supplementary Note 14]

A ceiling heat insulator,

-   -   wherein the ceiling heat insulator is located above a side wall        heat insulator of a heating apparatus for a substrate processing        apparatus, and    -   wherein the ceiling heat insulator includes a gas-flow path        having a space of a circular arc shape having its center at a        central portion of the ceiling heat insulator and allowing a        cooling gas to pass therethrough.        [Supplementary Note 15]

A method of manufacturing a semiconductor device, including,

-   -   cooling a substrate accommodated in a reaction container by        allowing a cooling gas to flow to a cooling gas flow path        located between the reaction container and a side wall heat        insulator positioned at an outer circumference of the reaction        container, and allowing the cooling gas to flow to a gas-flow        path located in a ceiling heat insulator,    -   wherein the ceiling heat insulator is located above the side        wall heat insulator and also includes the gas-flow path so that        the ceiling heat insulator has a solid cross-sectional area in        an outer edge side of the ceiling heat insulator that is smaller        than that in a center side of the ceiling heat insulator.        [Supplementary Note 16]

A method of manufacturing a semiconductor device, including,

-   -   cooling a substrate accommodated in a reaction container by        allowing a cooling gas to flow to a cooling gas flow path        located between the reaction container and a side wall heat        insulator positioned at an outer circumference of the reaction        container, and allowing the cooling gas to flow to a gas-flow        path located in a ceiling heat insulator,    -   wherein the gas-flow path is configured to have a space of a        circular arc shape having its center at a central portion of the        ceiling heat insulator, and    -   wherein the ceiling heat insulator is located above the side        wall heat insulator.        [Supplementary Note 17]

A method of manufacturing a semiconductor device, including,

-   -   heating a substrate accommodated in a reaction container by        using a heating apparatus,    -   wherein the heating apparatus including a side wall heat        insulator located at an outer circumference of the reaction        container, a ceiling heat insulator located above the side wall        heat insulator, a heating element located in an inner wall of        the side wall heat insulator, and a cooling gas flow path        located between the reaction container and the side wall heat        insulator, and    -   wherein the ceiling heat insulator includes a gas-flow path        located therein to allow a cooling gas to pass therethrough so        that the ceiling heat insulator has a solid cross-sectional area        in a circumference side of the ceiling heat insulator that is        smaller than that in a center side of the ceiling heat        insulator.        [Supplementary Note 18]

A method of manufacturing a semiconductor device, including,

-   -   heating a substrate accommodated in a reaction container by        using a heating apparatus,    -   wherein the heating apparatus includes a side wall heat        insulator located at an outer circumference of the reaction        container, a ceiling heat insulator located above the side wall        heat insulator, a heating element located in an inner wall of        the side wall heat insulator, and a cooling gas flow path        located between the reaction container and the side wall heat        insulator, and    -   wherein the ceiling heat insulator includes a gas-flow path        having a space of a circular arc shape having its center at a        central portion of the ceiling heat insulator and allowing a        cooling gas to pass therethrough.

According to the present disclosure, in-plane temperature uniformity ofa substrate can be improved.

While certain embodiments have been described, these embodiments havebeen presented by way of example only, and are not intended to limit thescope of the disclosures. Indeed, the novel methods and apparatusesdescribed herein may be embodied in a variety of other forms;furthermore, various omissions, substitutions and changes in the form ofthe embodiments described herein may be made without departing from thespirit of the disclosures. The accompanying claims and their equivalentsare intended to cover such forms or modifications as would fall withinthe scope and spirit of the disclosures.

What is claimed is:
 1. A ceiling heat insulator, which is located above a side wall heat insulator of a heating apparatus for a substrate processing apparatus for processing a substrate, the ceiling heat insulator comprising: an upper heat insulator; a lower heat insulator; and at least one gas-flow path allowing a cooling gas to pass therethrough so that the ceiling heat insulator includes a portion which has a solid cross-sectional area in an outer edge side of the ceiling heat insulator that is smaller than that in a center side of the ceiling heat insulator, wherein each of the upper heat insulator and the lower heat insulator includes a concave portion, which is located outside the substrate and has a circular arc shape, a center of the circular arc shape being located at a central portion of the ceiling heat insulator, and wherein the upper heat insulator and the lower heat insulator overlap with each other so that the concave portion of the upper heat insulator and the concave portion of the lower heat insulator are disposed to face each other and define the at least one gas-flow path.
 2. The ceiling heat insulator of claim 1, wherein the concave portion is formed to be symmetrical with respect to a central line on a horizontal plane of the ceiling heat insulator.
 3. The ceiling heat insulator of claim 1, wherein the at least one gas-flow path is configured so that a portion of the at least one gas-flow path formed in the upper heat insulator is wider than a portion of the at least one gas-flow path formed in the lower heat insulator in a vertical section.
 4. The ceiling heat insulator of claim 1, wherein the at least one gas-flow path is configured so that a portion of the at least one gas-flow path formed in the lower heat insulator is wider than a portion of the at least one gas-flow path formed in the upper heat insulator in a vertical section.
 5. The ceiling heat insulator of claim 1, wherein the at least one gas-flow path has a cross-sectional area that gets reduced toward the center side of the ceiling heat insulator.
 6. The ceiling heat insulator of claim 1, further comprising one or more insulating walls, wherein the at least one gas-flow path comprises a plurality of gas-flow paths, and wherein each of the insulating walls is located between the gas-flow paths so that each of the insulating walls divides the concave portions spatially.
 7. The ceiling heat insulator of claim 1, wherein the at least one gas-flow path comprises a plurality of gas-flow paths, and wherein each of the plurality of gas-flow paths includes a supply port configured to supply the cooling gas and an exhaust port configured to discharge the supplied cooling gas.
 8. The ceiling heat insulator of claim 7, wherein the supply ports included in the plurality of gas-flow paths are formed to be spaced apart from one another by 180° on a concentric circle having its center at the central portion of the ceiling heat insulator.
 9. The ceiling heat insulator of claim 7, wherein the exhaust ports included in the plurality of gas-flow paths are adjacent to one another on a lateral surface of the ceiling heat insulator.
 10. A heating apparatus, comprising the ceiling heat insulator of claim 1, wherein the heating apparatus further comprises: the side wall heat insulator located at an outer circumference of a reaction container; a heating element located on an inter wall of the side wall heat insulator; and a cooling gas flow path located between the reaction container and the side wall heat insulator.
 11. A substrate processing apparatus, comprising the heating apparatus of claim 10, wherein the substrate processing apparatus comprises the reaction container configured to accommodate the substrate located therein.
 12. A method of manufacturing a semiconductor device, comprising, cooling a substrate accommodated in a reaction container by allowing a cooling gas to flow to a first gas flow path installed between the reaction container and a side wall heat insulator positioned at an outer circumference of the reaction container, and allowing the first gas to flow to a second gas-flow path installed in a ceiling heat insulator, wherein the ceiling heat insulator is located above the side wall heat insulator and includes the second gas-flow path so that the ceiling heat insulator has a solid cross-sectional area in a circumference side of the ceiling heat insulator that is smaller than that in a center side of the ceiling heat insulator, wherein the ceiling heat insulator includes an upper heat insulator and a lower heat insulator, wherein each of the upper heat insulator and the lower heat insulator includes a concave portion, which is located outside the substrate and has a circular arc shape, a center of the circular arc shape being located at a central portion of the ceiling heat insulator, and wherein the upper heat insulator and the lower heat insulator overlap with each other so that the concave portion of the upper heat insulator and the concave portion of the lower heat insulator are disposed to face each other. 